Yeti Crab

The yeti crab is a family of deep-sea decapod crustaceans with hairy arms and a white shell.

The very first species (Kiwa hirsuta) of yeti crabs was only discovered in 2005 on a hydrothermal vent near Easter Island. Despite its small eyes and poor eyesight, the yeti crab has several unique adaptations to survive the harsh biome of the cold and desolate deep seafloor. Because they can only be reached by deep-sea submarines, there is still a lot we do not understand about them.

3 Incredible Yeti Crab Facts!

• One of the more interesting facts is that yeti crabs pile on top of each other to stay warm near hydrothermal vents. One scientist counted some 700 crabs per square meter.
• A genetic analysis suggests that the yeti crab family first evolved some 30 million years ago when their ancestors first colonized hydrothermal vent biomes.
• Because it lives deep in the water, the yeti crab has no need for color pigments, making it appear white or gray.

Classification and Scientific Name

The scientific name for the family of yeti crabs is Kiwa. It is named after the goddess of shellfish in Polynesian mythology. The yeti is not considered to be a member of the “true crabs,” but rather a closely related group called the squat lobsters, which includes the hermit crabs. More widely, they belong to the decapod order.

Species

There are currently five recognized species of yeti crabs:

• Kiwa hirsuta: This is the first species discovered back in 2005 by a group of researchers from the Monterey Bay Aquarium. The crab was so different from any other decapod that it warranted an entirely separate family. The name hirsute is actually a Latin word meaning “hairy.”
• Kiwa puravida: A second species was discovered in 2006 near the waters of Costa Rica. It has the same hairy claws as Kiwa hirsute.
• Kiwa tyleri: First discovered in 2010, this species resides in the East Scotia Ridge, just north of Antarctica. It was jokingly named the Hoff crab because its hairy chest resembled the actor David Hasselhoff. The conditions of its environment are extremely cold.
• Unnamed Species: A fourth unnamed species was first found in 2011 at a place called Longqi, or Dragon’s Breath, in the middle of the Indian Ocean. The claws of this species are comparatively quite short, and the hair is located on the chest like the Hoff crab. Based on genetic analysis, they seem to be somewhat closely related to Kiwa tyleri. They last shared a common ancestor some 1.5 million years ago.
• Kiwa araonae: This species was first discovered in 2013 near the Australian-Antarctic Ridge. While it does have long claws, it also lacks long, bristly hair.

Appearance

The yeti crab is characterized by a generally crab-like shape (the hard shell, the long appendages, and the big claws), but it also looks very much like the mythical snowman for which it was named. The defining features are the compact, all-white body, measuring about 6 inches long, and the long bristly claws that enable them to harvest bacteria.

Some have hairy chests in addition to or in place of the hairy claws. Because of its highly reduced eyes, it is thought to be completely or mostly blind.

Distribution, Population, and Habitat

The yeti crab is largely endemic to the cold habitats of the southern Pacific Ocean region, adjoining the waters of the Antarctic. The hydrothermal vents near which they live are essentially cracks in the deep-sea floor where mineral-rich scalding hot water escapes from the surface of the earth.

While they are highly adapted to their habitat, survival requires a very careful balance. If they stray too far from the vents, they can freeze to death in the frigid sea. However, if they wander too closely, they can overheat and die.

Because there is not enough data available about them, the IUCN Red List has never assessed the conservation status of any of the five known species.

Predators and Prey

Life near the hydrothermal vent is different from almost anywhere else on the planet. Organisms cannot rely on sunlight to capture energy, so they convert energy directly from the chemical flowing from the vents. The yeti crab’s role in this complex ecosystem is not yet fully understood, but we do know that it feeds on the bacteria flowing from the surface.

What eats the yeti crab?

The yeti crab does not seem to have many predators in its natural environment. It is thought that some deep-sea octopuses and fish may find them edible.

What does the yeti crab eat?

The entire diet of these crabs revolves around bacteria. By waving their hairy claws through the plumes of oxygen, methane, and hydrogen sulfide emanating from the vents, they essentially harvest the bacteria to feed upon. To the human eye, this strange movement looks kind of like a rhythmic dance.

Reproduction and Lifespan

The reproductive behavior and the lifespan of these crabs still remain a complete mystery. It is believed that the hydrothermal vents are too warm for their larvae to develop, so the female probably lays eggs in the colder waters. Very few other facts are known.

Fishing and Cooking

Because of its remote environment, these crabs are not used in cooking or fishing. Since no one has tried to taste them, it is not known if they are edible.